The present invention is directed to a surface sweeping machine, commonly referred to as a road sweeper, which utilizes gutter brushes and a pick-up head for delivering air-entrained debris into a hopper. The heavier debris falls to the bottom of the hopper and lighter dust enters a centrifugal separator which separates the dust from the air, delivers the dust to the hopper, and the cleaner air is recirculated along a generally continuous path of travel to the pick-up head and back to the hopper.
Typical road sweepers or street sweepers of the type aforesaid are disclosed in commonly assigned U.S. Pat. Nos. 3,512,206; 3,545,181; 3,790,981 and 4,660,248 issued respectively on Aug. 30, 1966; Feb. 12, 1974 and Apr. 28, 1987. The totality of the disclosures of the latter-identified patents are incorporated hereat by reference, particularly in regard to details of construction, including, but not limited to, the gutter brushes, the pick-up head, the centrifugal separator, etc.
The street sweeper of U.S. Pat. Nos. 3,512,206 and 3,545,181 is quite typical in its construction and includes a conventional vehicle or truck having a frame, a cab, an auxiliary engine behind the cab for driving a turbine of the centrifugal separator, a continuous closed path air circulating system, and a hopper at the rear end of the frame having an outlet normally closed by a door. When the hopper is filled with debris, the street sweeper is driven to a dump site, the hopper door is then opened to discharge the debris, and the hopper is tilted or pivoted to augment the discharge of the debris through the now opened hopper door. Such conventional rear-dumping hoppers are well known but have obvious draw-backs, particularly associated with rearward visibility as, for example, when the street sweeper is backed into the dump site area.
Disadvantages of such rear-dumping vehicles are acknowledged and set forth in U.S. Pat. Nos. 4,236,756; 4,171,551; 4,178,647; 4,222,141 and 4,343,060 issued respectively on Dec. 2, 1980; Oct. 23, 1979; Dec. 18, 1979; Sep. 16, 1980 and Aug. 10, 1982 in the names of Donald L. Hildebrand et al., particularly with respect to the disadvantages of rearward visibility and the acknowledged advantages of forward visibility associated with forward dumping, high dumping or over-the-cab dumping of hoppers associated with street sweepers. The subject matter of the latter patents was commercially manufactured by the common assignee for several years, but is no longer being manufactured thereby. However, high dump or forward-dumping of street sweeper hoppers remains viable, particularly when, as in the present case, it is intended that the hopper be dumped into a dump truck or like vehicle. Thus, with the high dump street sweeper of the present invention it is unnecessary to back the street sweeper toward the vehicle into which the debris of the hopper is to be dumped, and instead the street sweeper is simply driven adjacent the dump truck and the debris from the street sweeper hopper is dumped forwardly over-the-cab with the attendant desirable forward visibility heretofore noted.